Another witness told the RTL TV channel: "I just saw a plane lose its right wing in mid-flight and crash. I heard a massive 'bang' ... I didn't see anyone escape with a parachute."

Jean-Claude Nihoul, Mayor of Fernelmont, said: "Three parachutes open on the ground show that three people tried to jump," adding: "it is a tragedy that we had never known in the region."

The reason for the accident is not yet known but investigators have been summoned to the site to find out why the plane suddenly plunged to the ground from a height of around 3,000m.

Nicolas Hormans of the Paraclub Namur, whose skydivers were among the victims, told RTL network that the nosedive would have thrown everyone on board around with such force they would been unable to jump out and parachute to safety.

Efforts are also being made to confirm the identities of those who died.

Firefighters rushed to the scene, some 75 km (47 miles) south-east of Brussels, but are understood to have been unable to save any of those on board.

Prime Minister Elio Di Rupo confirmed the news soon after, saying his thoughts were with the families of the victims.

The Prime Minister, the Belgian King Philippe and the country's interior minister later visited the scene.